2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 #include <lttng/ust-ctl.h>
27 #include <sys/socket.h>
29 #include <sys/types.h>
32 #include <urcu/list.h>
35 #include <common/common.h>
36 #include <common/sessiond-comm/sessiond-comm.h>
37 #include <common/relayd/relayd.h>
38 #include <common/compat/fcntl.h>
39 #include <common/consumer-metadata-cache.h>
40 #include <common/consumer-stream.h>
41 #include <common/consumer-timer.h>
42 #include <common/utils.h>
44 #include "ust-consumer.h"
46 extern struct lttng_consumer_global_data consumer_data
;
47 extern int consumer_poll_timeout
;
48 extern volatile int consumer_quit
;
51 * Free channel object and all streams associated with it. This MUST be used
52 * only and only if the channel has _NEVER_ been added to the global channel
55 static void destroy_channel(struct lttng_consumer_channel
*channel
)
57 struct lttng_consumer_stream
*stream
, *stmp
;
61 DBG("UST consumer cleaning stream list");
63 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
65 cds_list_del(&stream
->send_node
);
66 ustctl_destroy_stream(stream
->ustream
);
71 * If a channel is available meaning that was created before the streams
75 lttng_ustconsumer_del_channel(channel
);
81 * Add channel to internal consumer state.
83 * Returns 0 on success or else a negative value.
85 static int add_channel(struct lttng_consumer_channel
*channel
,
86 struct lttng_consumer_local_data
*ctx
)
93 if (ctx
->on_recv_channel
!= NULL
) {
94 ret
= ctx
->on_recv_channel(channel
);
96 ret
= consumer_add_channel(channel
, ctx
);
98 /* Most likely an ENOMEM. */
99 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
103 ret
= consumer_add_channel(channel
, ctx
);
106 DBG("UST consumer channel added (key: %" PRIu64
")", channel
->key
);
113 * Allocate and return a consumer channel object.
115 static struct lttng_consumer_channel
*allocate_channel(uint64_t session_id
,
116 const char *pathname
, const char *name
, uid_t uid
, gid_t gid
,
117 uint64_t relayd_id
, uint64_t key
, enum lttng_event_output output
,
118 uint64_t tracefile_size
, uint64_t tracefile_count
,
119 uint64_t session_id_per_pid
, unsigned int monitor
)
124 return consumer_allocate_channel(key
, session_id
, pathname
, name
, uid
,
125 gid
, relayd_id
, output
, tracefile_size
,
126 tracefile_count
, session_id_per_pid
, monitor
);
130 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
131 * error value if applicable is set in it else it is kept untouched.
133 * Return NULL on error else the newly allocated stream object.
135 static struct lttng_consumer_stream
*allocate_stream(int cpu
, int key
,
136 struct lttng_consumer_channel
*channel
,
137 struct lttng_consumer_local_data
*ctx
, int *_alloc_ret
)
140 struct lttng_consumer_stream
*stream
= NULL
;
145 stream
= consumer_allocate_stream(channel
->key
,
147 LTTNG_CONSUMER_ACTIVE_STREAM
,
157 if (stream
== NULL
) {
161 * We could not find the channel. Can happen if cpu hotplug
162 * happens while tearing down.
164 DBG3("Could not find channel");
169 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_OUTFD_ERROR
);
175 stream
->chan
= channel
;
179 *_alloc_ret
= alloc_ret
;
185 * Send the given stream pointer to the corresponding thread.
187 * Returns 0 on success else a negative value.
189 static int send_stream_to_thread(struct lttng_consumer_stream
*stream
,
190 struct lttng_consumer_local_data
*ctx
)
193 struct lttng_pipe
*stream_pipe
;
195 /* Get the right pipe where the stream will be sent. */
196 if (stream
->metadata_flag
) {
197 stream_pipe
= ctx
->consumer_metadata_pipe
;
199 stream_pipe
= ctx
->consumer_data_pipe
;
202 ret
= lttng_pipe_write(stream_pipe
, &stream
, sizeof(stream
));
204 ERR("Consumer write %s stream to pipe %d",
205 stream
->metadata_flag
? "metadata" : "data",
206 lttng_pipe_get_writefd(stream_pipe
));
213 * Create streams for the given channel using liblttng-ust-ctl.
215 * Return 0 on success else a negative value.
217 static int create_ust_streams(struct lttng_consumer_channel
*channel
,
218 struct lttng_consumer_local_data
*ctx
)
221 struct ustctl_consumer_stream
*ustream
;
222 struct lttng_consumer_stream
*stream
;
228 * While a stream is available from ustctl. When NULL is returned, we've
229 * reached the end of the possible stream for the channel.
231 while ((ustream
= ustctl_create_stream(channel
->uchan
, cpu
))) {
234 wait_fd
= ustctl_stream_get_wait_fd(ustream
);
236 /* Allocate consumer stream object. */
237 stream
= allocate_stream(cpu
, wait_fd
, channel
, ctx
, &ret
);
241 stream
->ustream
= ustream
;
243 * Store it so we can save multiple function calls afterwards since
244 * this value is used heavily in the stream threads. This is UST
245 * specific so this is why it's done after allocation.
247 stream
->wait_fd
= wait_fd
;
250 * Increment channel refcount since the channel reference has now been
251 * assigned in the allocation process above.
253 if (stream
->chan
->monitor
) {
254 uatomic_inc(&stream
->chan
->refcount
);
258 * Order is important this is why a list is used. On error, the caller
259 * should clean this list.
261 cds_list_add_tail(&stream
->send_node
, &channel
->streams
.head
);
263 ret
= ustctl_get_max_subbuf_size(stream
->ustream
,
264 &stream
->max_sb_size
);
266 ERR("ustctl_get_max_subbuf_size failed for stream %s",
271 /* Do actions once stream has been received. */
272 if (ctx
->on_recv_stream
) {
273 ret
= ctx
->on_recv_stream(stream
);
279 DBG("UST consumer add stream %s (key: %" PRIu64
") with relayd id %" PRIu64
,
280 stream
->name
, stream
->key
, stream
->relayd_stream_id
);
282 /* Set next CPU stream. */
283 channel
->streams
.count
= ++cpu
;
285 /* Keep stream reference when creating metadata. */
286 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
) {
287 channel
->metadata_stream
= stream
;
299 * Create an UST channel with the given attributes and send it to the session
300 * daemon using the ust ctl API.
302 * Return 0 on success or else a negative value.
304 static int create_ust_channel(struct ustctl_consumer_channel_attr
*attr
,
305 struct ustctl_consumer_channel
**chanp
)
308 struct ustctl_consumer_channel
*channel
;
313 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
314 "subbuf_size: %" PRIu64
", num_subbuf: %" PRIu64
", "
315 "switch_timer_interval: %u, read_timer_interval: %u, "
316 "output: %d, type: %d", attr
->overwrite
, attr
->subbuf_size
,
317 attr
->num_subbuf
, attr
->switch_timer_interval
,
318 attr
->read_timer_interval
, attr
->output
, attr
->type
);
320 channel
= ustctl_create_channel(attr
);
335 * Send a single given stream to the session daemon using the sock.
337 * Return 0 on success else a negative value.
339 static int send_sessiond_stream(int sock
, struct lttng_consumer_stream
*stream
)
346 DBG2("UST consumer sending stream %" PRIu64
" to sessiond", stream
->key
);
348 /* Send stream to session daemon. */
349 ret
= ustctl_send_stream_to_sessiond(sock
, stream
->ustream
);
359 * Send channel to sessiond.
361 * Return 0 on success or else a negative value.
363 static int send_sessiond_channel(int sock
,
364 struct lttng_consumer_channel
*channel
,
365 struct lttng_consumer_local_data
*ctx
, int *relayd_error
)
367 int ret
, ret_code
= LTTNG_OK
;
368 struct lttng_consumer_stream
*stream
;
374 DBG("UST consumer sending channel %s to sessiond", channel
->name
);
376 if (channel
->relayd_id
!= (uint64_t) -1ULL) {
377 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
378 /* Try to send the stream to the relayd if one is available. */
379 ret
= consumer_send_relayd_stream(stream
, stream
->chan
->pathname
);
382 * Flag that the relayd was the problem here probably due to a
383 * communicaton error on the socket.
388 ret_code
= LTTNG_ERR_RELAYD_CONNECT_FAIL
;
393 /* Inform sessiond that we are about to send channel and streams. */
394 ret
= consumer_send_status_msg(sock
, ret_code
);
395 if (ret
< 0 || ret_code
!= LTTNG_OK
) {
397 * Either the session daemon is not responding or the relayd died so we
403 /* Send channel to sessiond. */
404 ret
= ustctl_send_channel_to_sessiond(sock
, channel
->uchan
);
409 ret
= ustctl_channel_close_wakeup_fd(channel
->uchan
);
414 /* The channel was sent successfully to the sessiond at this point. */
415 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
416 /* Send stream to session daemon. */
417 ret
= send_sessiond_stream(sock
, stream
);
423 /* Tell sessiond there is no more stream. */
424 ret
= ustctl_send_stream_to_sessiond(sock
, NULL
);
429 DBG("UST consumer NULL stream sent to sessiond");
434 if (ret_code
!= LTTNG_OK
) {
441 * Creates a channel and streams and add the channel it to the channel internal
442 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
445 * Return 0 on success or else, a negative value is returned and the channel
446 * MUST be destroyed by consumer_del_channel().
448 static int ask_channel(struct lttng_consumer_local_data
*ctx
, int sock
,
449 struct lttng_consumer_channel
*channel
,
450 struct ustctl_consumer_channel_attr
*attr
)
459 * This value is still used by the kernel consumer since for the kernel,
460 * the stream ownership is not IN the consumer so we need to have the
461 * number of left stream that needs to be initialized so we can know when
462 * to delete the channel (see consumer.c).
464 * As for the user space tracer now, the consumer creates and sends the
465 * stream to the session daemon which only sends them to the application
466 * once every stream of a channel is received making this value useless
467 * because we they will be added to the poll thread before the application
468 * receives them. This ensures that a stream can not hang up during
469 * initilization of a channel.
471 channel
->nb_init_stream_left
= 0;
473 /* The reply msg status is handled in the following call. */
474 ret
= create_ust_channel(attr
, &channel
->uchan
);
479 channel
->wait_fd
= ustctl_channel_get_wait_fd(channel
->uchan
);
482 * For the snapshots (no monitor), we create the metadata streams
483 * on demand, not during the channel creation.
485 if (channel
->type
== CONSUMER_CHANNEL_TYPE_METADATA
&& !channel
->monitor
) {
490 /* Open all streams for this channel. */
491 ret
= create_ust_streams(channel
, ctx
);
501 * Send all stream of a channel to the right thread handling it.
503 * On error, return a negative value else 0 on success.
505 static int send_streams_to_thread(struct lttng_consumer_channel
*channel
,
506 struct lttng_consumer_local_data
*ctx
)
509 struct lttng_consumer_stream
*stream
, *stmp
;
514 /* Send streams to the corresponding thread. */
515 cds_list_for_each_entry_safe(stream
, stmp
, &channel
->streams
.head
,
517 /* Sending the stream to the thread. */
518 ret
= send_stream_to_thread(stream
, ctx
);
521 * If we are unable to send the stream to the thread, there is
522 * a big problem so just stop everything.
527 /* Remove node from the channel stream list. */
528 cds_list_del(&stream
->send_node
);
531 * From this point on, the stream's ownership has been moved away from
532 * the channel and becomes globally visible.
534 stream
->globally_visible
= 1;
542 * Write metadata to the given channel using ustctl to convert the string to
544 * Called only from consumer_metadata_cache_write.
545 * The metadata cache lock MUST be acquired to write in the cache.
547 * Return 0 on success else a negative value.
549 int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel
*metadata
,
550 const char *metadata_str
, uint64_t target_offset
, uint64_t len
)
555 assert(metadata_str
);
557 DBG("UST consumer writing metadata to channel %s", metadata
->name
);
559 if (!metadata
->metadata_stream
) {
564 assert(target_offset
<= metadata
->metadata_cache
->max_offset
);
565 ret
= ustctl_write_metadata_to_channel(metadata
->uchan
,
566 metadata_str
+ target_offset
, len
);
568 ERR("ustctl write metadata fail with ret %d, len %" PRIu64
, ret
, len
);
572 ustctl_flush_buffer(metadata
->metadata_stream
->ustream
, 1);
579 * Flush channel's streams using the given key to retrieve the channel.
581 * Return 0 on success else an LTTng error code.
583 static int flush_channel(uint64_t chan_key
)
586 struct lttng_consumer_channel
*channel
;
587 struct lttng_consumer_stream
*stream
;
589 struct lttng_ht_iter iter
;
591 DBG("UST consumer flush channel key %" PRIu64
, chan_key
);
594 channel
= consumer_find_channel(chan_key
);
596 ERR("UST consumer flush channel %" PRIu64
" not found", chan_key
);
597 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
601 ht
= consumer_data
.stream_per_chan_id_ht
;
603 /* For each stream of the channel id, flush it. */
604 cds_lfht_for_each_entry_duplicate(ht
->ht
,
605 ht
->hash_fct(&channel
->key
, lttng_ht_seed
), ht
->match_fct
,
606 &channel
->key
, &iter
.iter
, stream
, node_channel_id
.node
) {
607 ustctl_flush_buffer(stream
->ustream
, 1);
615 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
616 * RCU read side lock MUST be acquired before calling this function.
618 * Return 0 on success else an LTTng error code.
620 static int close_metadata(uint64_t chan_key
)
623 struct lttng_consumer_channel
*channel
;
625 DBG("UST consumer close metadata key %" PRIu64
, chan_key
);
627 channel
= consumer_find_channel(chan_key
);
630 * This is possible if the metadata thread has issue a delete because
631 * the endpoint point of the stream hung up. There is no way the
632 * session daemon can know about it thus use a DBG instead of an actual
635 DBG("UST consumer close metadata %" PRIu64
" not found", chan_key
);
636 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
640 pthread_mutex_lock(&consumer_data
.lock
);
642 if (cds_lfht_is_node_deleted(&channel
->node
.node
)) {
646 if (channel
->switch_timer_enabled
== 1) {
647 DBG("Deleting timer on metadata channel");
648 consumer_timer_switch_stop(channel
);
651 if (channel
->metadata_stream
) {
652 ret
= ustctl_stream_close_wakeup_fd(channel
->metadata_stream
->ustream
);
654 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret
);
655 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
661 pthread_mutex_unlock(&consumer_data
.lock
);
667 * RCU read side lock MUST be acquired before calling this function.
669 * Return 0 on success else an LTTng error code.
671 static int setup_metadata(struct lttng_consumer_local_data
*ctx
, uint64_t key
)
674 struct lttng_consumer_channel
*metadata
;
676 DBG("UST consumer setup metadata key %" PRIu64
, key
);
678 metadata
= consumer_find_channel(key
);
680 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
681 ret
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
686 * In no monitor mode, the metadata channel has no stream(s) so skip the
687 * ownership transfer to the metadata thread.
689 if (!metadata
->monitor
) {
690 DBG("Metadata channel in no monitor");
696 * Send metadata stream to relayd if one available. Availability is
697 * known if the stream is still in the list of the channel.
699 if (cds_list_empty(&metadata
->streams
.head
)) {
700 ERR("Metadata channel key %" PRIu64
", no stream available.", key
);
701 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
702 goto error_no_stream
;
705 /* Send metadata stream to relayd if needed. */
706 if (metadata
->metadata_stream
->net_seq_idx
!= (uint64_t) -1ULL) {
707 ret
= consumer_send_relayd_stream(metadata
->metadata_stream
,
710 ret
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
715 ret
= send_streams_to_thread(metadata
, ctx
);
718 * If we are unable to send the stream to the thread, there is
719 * a big problem so just stop everything.
721 ret
= LTTCOMM_CONSUMERD_FATAL
;
724 /* List MUST be empty after or else it could be reused. */
725 assert(cds_list_empty(&metadata
->streams
.head
));
732 * Delete metadata channel on error. At this point, the metadata stream can
733 * NOT be monitored by the metadata thread thus having the guarantee that
734 * the stream is still in the local stream list of the channel. This call
735 * will make sure to clean that list.
737 cds_list_del(&metadata
->metadata_stream
->send_node
);
738 consumer_stream_destroy(metadata
->metadata_stream
, NULL
);
745 * Snapshot the whole metadata.
747 * Returns 0 on success, < 0 on error
749 static int snapshot_metadata(uint64_t key
, char *path
, uint64_t relayd_id
,
750 struct lttng_consumer_local_data
*ctx
)
754 uint64_t total_len
= 0;
755 struct lttng_consumer_channel
*metadata_channel
;
756 struct lttng_consumer_stream
*metadata_stream
;
761 DBG("UST consumer snapshot metadata with key %" PRIu64
" at path %s",
766 metadata_channel
= consumer_find_channel(key
);
767 if (!metadata_channel
) {
768 ERR("UST snapshot metadata channel not found for key %lu", key
);
772 assert(!metadata_channel
->monitor
);
775 * Ask the sessiond if we have new metadata waiting and update the
776 * consumer metadata cache.
778 ret
= lttng_ustconsumer_request_metadata(ctx
, metadata_channel
);
784 * The metadata stream is NOT created in no monitor mode when the channel
785 * is created on a sessiond ask channel command.
787 ret
= create_ust_streams(metadata_channel
, ctx
);
792 metadata_stream
= metadata_channel
->metadata_stream
;
793 assert(metadata_stream
);
795 if (relayd_id
!= (uint64_t) -1ULL) {
796 metadata_stream
->net_seq_idx
= relayd_id
;
797 ret
= consumer_send_relayd_stream(metadata_stream
, path
);
802 ret
= utils_create_stream_file(path
, metadata_stream
->name
,
803 metadata_stream
->chan
->tracefile_size
,
804 metadata_stream
->tracefile_count_current
,
805 metadata_stream
->uid
, metadata_stream
->gid
);
809 metadata_stream
->out_fd
= ret
;
810 metadata_stream
->tracefile_size_current
= 0;
813 pthread_mutex_lock(&metadata_channel
->metadata_cache
->lock
);
814 while (total_len
< metadata_channel
->metadata_cache
->total_bytes_written
) {
816 * Write at most one packet of metadata into the channel
817 * to avoid blocking here.
819 write_len
= ustctl_write_one_packet_to_channel(metadata_channel
->uchan
,
820 metadata_channel
->metadata_cache
->data
,
821 metadata_channel
->metadata_cache
->total_bytes_written
);
823 ERR("UST consumer snapshot writing metadata packet");
827 total_len
+= write_len
;
829 DBG("Written %" PRIu64
" bytes to metadata (left: %" PRIu64
")",
831 metadata_channel
->metadata_cache
->total_bytes_written
- write_len
);
832 ustctl_flush_buffer(metadata_stream
->ustream
, 1);
833 ret
= lttng_consumer_read_subbuffer(metadata_stream
, ctx
);
840 pthread_mutex_unlock(&metadata_channel
->metadata_cache
->lock
);
844 * Clean up the stream completly because the next snapshot will use a new
847 cds_list_del(&metadata_stream
->send_node
);
848 consumer_stream_destroy(metadata_stream
, NULL
);
849 metadata_channel
->metadata_stream
= NULL
;
857 * Take a snapshot of all the stream of a channel.
859 * Returns 0 on success, < 0 on error
861 static int snapshot_channel(uint64_t key
, char *path
, uint64_t relayd_id
,
862 uint64_t max_stream_size
, struct lttng_consumer_local_data
*ctx
)
865 unsigned use_relayd
= 0;
866 unsigned long consumed_pos
, produced_pos
;
867 struct lttng_consumer_channel
*channel
;
868 struct lttng_consumer_stream
*stream
;
875 if (relayd_id
!= (uint64_t) -1ULL) {
879 channel
= consumer_find_channel(key
);
881 ERR("UST snapshot channel not found for key %lu", key
);
885 assert(!channel
->monitor
);
886 DBG("UST consumer snapshot channel %lu", key
);
888 cds_list_for_each_entry(stream
, &channel
->streams
.head
, send_node
) {
889 /* Lock stream because we are about to change its state. */
890 pthread_mutex_lock(&stream
->lock
);
891 stream
->net_seq_idx
= relayd_id
;
894 ret
= consumer_send_relayd_stream(stream
, path
);
899 ret
= utils_create_stream_file(path
, stream
->name
,
900 stream
->chan
->tracefile_size
,
901 stream
->tracefile_count_current
,
902 stream
->uid
, stream
->gid
);
906 stream
->out_fd
= ret
;
907 stream
->tracefile_size_current
= 0;
909 DBG("UST consumer snapshot stream %s/%s (%" PRIu64
")", path
,
910 stream
->name
, stream
->key
);
913 ustctl_flush_buffer(stream
->ustream
, 1);
915 ret
= lttng_ustconsumer_take_snapshot(stream
);
917 ERR("Taking UST snapshot");
921 ret
= lttng_ustconsumer_get_produced_snapshot(stream
, &produced_pos
);
923 ERR("Produced UST snapshot position");
927 ret
= lttng_ustconsumer_get_consumed_snapshot(stream
, &consumed_pos
);
929 ERR("Consumerd UST snapshot position");
934 * The original value is sent back if max stream size is larger than
935 * the possible size of the snapshot. Also, we asume that the session
936 * daemon should never send a maximum stream size that is lower than
939 consumed_pos
= consumer_get_consumed_maxsize(consumed_pos
,
940 produced_pos
, max_stream_size
);
942 while (consumed_pos
< produced_pos
) {
944 unsigned long len
, padded_len
;
946 DBG("UST consumer taking snapshot at pos %lu", consumed_pos
);
948 ret
= ustctl_get_subbuf(stream
->ustream
, &consumed_pos
);
950 if (ret
!= -EAGAIN
) {
951 PERROR("ustctl_get_subbuf snapshot");
952 goto error_close_stream
;
954 DBG("UST consumer get subbuf failed. Skipping it.");
955 consumed_pos
+= stream
->max_sb_size
;
959 ret
= ustctl_get_subbuf_size(stream
->ustream
, &len
);
961 ERR("Snapshot ustctl_get_subbuf_size");
962 goto error_put_subbuf
;
965 ret
= ustctl_get_padded_subbuf_size(stream
->ustream
, &padded_len
);
967 ERR("Snapshot ustctl_get_padded_subbuf_size");
968 goto error_put_subbuf
;
971 read_len
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
,
974 if (read_len
!= len
) {
976 goto error_put_subbuf
;
979 if (read_len
!= padded_len
) {
981 goto error_put_subbuf
;
985 ret
= ustctl_put_subbuf(stream
->ustream
);
987 ERR("Snapshot ustctl_put_subbuf");
988 goto error_close_stream
;
990 consumed_pos
+= stream
->max_sb_size
;
993 /* Simply close the stream so we can use it on the next snapshot. */
994 consumer_stream_close(stream
);
995 pthread_mutex_unlock(&stream
->lock
);
1002 if (ustctl_put_subbuf(stream
->ustream
) < 0) {
1003 ERR("Snapshot ustctl_put_subbuf");
1006 consumer_stream_close(stream
);
1008 pthread_mutex_unlock(&stream
->lock
);
1015 * Receive the metadata updates from the sessiond.
1017 int lttng_ustconsumer_recv_metadata(int sock
, uint64_t key
, uint64_t offset
,
1018 uint64_t len
, struct lttng_consumer_channel
*channel
)
1020 int ret
, ret_code
= LTTNG_OK
;
1023 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
, len
);
1025 metadata_str
= zmalloc(len
* sizeof(char));
1026 if (!metadata_str
) {
1027 PERROR("zmalloc metadata string");
1028 ret_code
= LTTCOMM_CONSUMERD_ENOMEM
;
1032 /* Receive metadata string. */
1033 ret
= lttcomm_recv_unix_sock(sock
, metadata_str
, len
);
1035 /* Session daemon is dead so return gracefully. */
1041 * XXX: The consumer data lock is acquired before calling metadata cache
1042 * write which calls push metadata that MUST be protected by the consumer
1043 * lock in order to be able to check the validity of the metadata stream of
1046 * Note that this will be subject to change to better fine grained locking
1047 * and ultimately try to get rid of this global consumer data lock.
1049 pthread_mutex_lock(&consumer_data
.lock
);
1051 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
1052 ret
= consumer_metadata_cache_write(channel
, offset
, len
, metadata_str
);
1054 /* Unable to handle metadata. Notify session daemon. */
1055 ret_code
= LTTCOMM_CONSUMERD_ERROR_METADATA
;
1057 * Skip metadata flush on write error since the offset and len might
1058 * not have been updated which could create an infinite loop below when
1059 * waiting for the metadata cache to be flushed.
1061 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1062 pthread_mutex_unlock(&consumer_data
.lock
);
1065 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
1066 pthread_mutex_unlock(&consumer_data
.lock
);
1068 while (consumer_metadata_cache_flushed(channel
, offset
+ len
)) {
1069 DBG("Waiting for metadata to be flushed");
1070 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME
);
1080 * Receive command from session daemon and process it.
1082 * Return 1 on success else a negative value or 0.
1084 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
1085 int sock
, struct pollfd
*consumer_sockpoll
)
1088 enum lttng_error_code ret_code
= LTTNG_OK
;
1089 struct lttcomm_consumer_msg msg
;
1090 struct lttng_consumer_channel
*channel
= NULL
;
1092 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
1093 if (ret
!= sizeof(msg
)) {
1094 DBG("Consumer received unexpected message size %zd (expects %zu)",
1097 * The ret value might 0 meaning an orderly shutdown but this is ok
1098 * since the caller handles this.
1101 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1106 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
1108 * Notify the session daemon that the command is completed.
1110 * On transport layer error, the function call will print an error
1111 * message so handling the returned code is a bit useless since we
1112 * return an error code anyway.
1114 (void) consumer_send_status_msg(sock
, ret_code
);
1118 /* relayd needs RCU read-side lock */
1121 switch (msg
.cmd_type
) {
1122 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
1124 /* Session daemon status message are handled in the following call. */
1125 ret
= consumer_add_relayd_socket(msg
.u
.relayd_sock
.net_index
,
1126 msg
.u
.relayd_sock
.type
, ctx
, sock
, consumer_sockpoll
,
1127 &msg
.u
.relayd_sock
.sock
, msg
.u
.relayd_sock
.session_id
);
1130 case LTTNG_CONSUMER_DESTROY_RELAYD
:
1132 uint64_t index
= msg
.u
.destroy_relayd
.net_seq_idx
;
1133 struct consumer_relayd_sock_pair
*relayd
;
1135 DBG("UST consumer destroying relayd %" PRIu64
, index
);
1137 /* Get relayd reference if exists. */
1138 relayd
= consumer_find_relayd(index
);
1139 if (relayd
== NULL
) {
1140 DBG("Unable to find relayd %" PRIu64
, index
);
1141 ret_code
= LTTNG_ERR_NO_CONSUMER
;
1145 * Each relayd socket pair has a refcount of stream attached to it
1146 * which tells if the relayd is still active or not depending on the
1149 * This will set the destroy flag of the relayd object and destroy it
1150 * if the refcount reaches zero when called.
1152 * The destroy can happen either here or when a stream fd hangs up.
1155 consumer_flag_relayd_for_destroy(relayd
);
1158 goto end_msg_sessiond
;
1160 case LTTNG_CONSUMER_UPDATE_STREAM
:
1165 case LTTNG_CONSUMER_DATA_PENDING
:
1167 int ret
, is_data_pending
;
1168 uint64_t id
= msg
.u
.data_pending
.session_id
;
1170 DBG("UST consumer data pending command for id %" PRIu64
, id
);
1172 is_data_pending
= consumer_data_pending(id
);
1174 /* Send back returned value to session daemon */
1175 ret
= lttcomm_send_unix_sock(sock
, &is_data_pending
,
1176 sizeof(is_data_pending
));
1178 DBG("Error when sending the data pending ret code: %d", ret
);
1183 * No need to send back a status message since the data pending
1184 * returned value is the response.
1188 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION
:
1191 struct ustctl_consumer_channel_attr attr
;
1193 /* Create a plain object and reserve a channel key. */
1194 channel
= allocate_channel(msg
.u
.ask_channel
.session_id
,
1195 msg
.u
.ask_channel
.pathname
, msg
.u
.ask_channel
.name
,
1196 msg
.u
.ask_channel
.uid
, msg
.u
.ask_channel
.gid
,
1197 msg
.u
.ask_channel
.relayd_id
, msg
.u
.ask_channel
.key
,
1198 (enum lttng_event_output
) msg
.u
.ask_channel
.output
,
1199 msg
.u
.ask_channel
.tracefile_size
,
1200 msg
.u
.ask_channel
.tracefile_count
,
1201 msg
.u
.ask_channel
.session_id_per_pid
,
1202 msg
.u
.ask_channel
.monitor
);
1204 goto end_channel_error
;
1207 /* Build channel attributes from received message. */
1208 attr
.subbuf_size
= msg
.u
.ask_channel
.subbuf_size
;
1209 attr
.num_subbuf
= msg
.u
.ask_channel
.num_subbuf
;
1210 attr
.overwrite
= msg
.u
.ask_channel
.overwrite
;
1211 attr
.switch_timer_interval
= msg
.u
.ask_channel
.switch_timer_interval
;
1212 attr
.read_timer_interval
= msg
.u
.ask_channel
.read_timer_interval
;
1213 attr
.chan_id
= msg
.u
.ask_channel
.chan_id
;
1214 attr
.output
= msg
.u
.ask_channel
.output
;
1215 memcpy(attr
.uuid
, msg
.u
.ask_channel
.uuid
, sizeof(attr
.uuid
));
1217 /* Translate and save channel type. */
1218 switch (msg
.u
.ask_channel
.type
) {
1219 case LTTNG_UST_CHAN_PER_CPU
:
1220 channel
->type
= CONSUMER_CHANNEL_TYPE_DATA
;
1221 attr
.type
= LTTNG_UST_CHAN_PER_CPU
;
1223 * Set refcount to 1 for owner. Below, we will
1224 * pass ownership to the
1225 * consumer_thread_channel_poll() thread.
1227 channel
->refcount
= 1;
1229 case LTTNG_UST_CHAN_METADATA
:
1230 channel
->type
= CONSUMER_CHANNEL_TYPE_METADATA
;
1231 attr
.type
= LTTNG_UST_CHAN_METADATA
;
1238 ret
= ask_channel(ctx
, sock
, channel
, &attr
);
1240 goto end_channel_error
;
1243 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1244 ret
= consumer_metadata_cache_allocate(channel
);
1246 ERR("Allocating metadata cache");
1247 goto end_channel_error
;
1249 consumer_timer_switch_start(channel
, attr
.switch_timer_interval
);
1250 attr
.switch_timer_interval
= 0;
1254 * Add the channel to the internal state AFTER all streams were created
1255 * and successfully sent to session daemon. This way, all streams must
1256 * be ready before this channel is visible to the threads.
1257 * If add_channel succeeds, ownership of the channel is
1258 * passed to consumer_thread_channel_poll().
1260 ret
= add_channel(channel
, ctx
);
1262 if (msg
.u
.ask_channel
.type
== LTTNG_UST_CHAN_METADATA
) {
1263 if (channel
->switch_timer_enabled
== 1) {
1264 consumer_timer_switch_stop(channel
);
1266 consumer_metadata_cache_destroy(channel
);
1268 goto end_channel_error
;
1272 * Channel and streams are now created. Inform the session daemon that
1273 * everything went well and should wait to receive the channel and
1274 * streams with ustctl API.
1276 ret
= consumer_send_status_channel(sock
, channel
);
1279 * There is probably a problem on the socket.
1286 case LTTNG_CONSUMER_GET_CHANNEL
:
1288 int ret
, relayd_err
= 0;
1289 uint64_t key
= msg
.u
.get_channel
.key
;
1290 struct lttng_consumer_channel
*channel
;
1292 channel
= consumer_find_channel(key
);
1294 ERR("UST consumer get channel key %" PRIu64
" not found", key
);
1295 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1296 goto end_msg_sessiond
;
1299 /* Send everything to sessiond. */
1300 ret
= send_sessiond_channel(sock
, channel
, ctx
, &relayd_err
);
1304 * We were unable to send to the relayd the stream so avoid
1305 * sending back a fatal error to the thread since this is OK
1306 * and the consumer can continue its work. The above call
1307 * has sent the error status message to the sessiond.
1312 * The communicaton was broken hence there is a bad state between
1313 * the consumer and sessiond so stop everything.
1319 * In no monitor mode, the streams ownership is kept inside the channel
1320 * so don't send them to the data thread.
1322 if (!channel
->monitor
) {
1323 goto end_msg_sessiond
;
1326 ret
= send_streams_to_thread(channel
, ctx
);
1329 * If we are unable to send the stream to the thread, there is
1330 * a big problem so just stop everything.
1334 /* List MUST be empty after or else it could be reused. */
1335 assert(cds_list_empty(&channel
->streams
.head
));
1336 goto end_msg_sessiond
;
1338 case LTTNG_CONSUMER_DESTROY_CHANNEL
:
1340 uint64_t key
= msg
.u
.destroy_channel
.key
;
1343 * Only called if streams have not been sent to stream
1344 * manager thread. However, channel has been sent to
1345 * channel manager thread.
1347 notify_thread_del_channel(ctx
, key
);
1348 goto end_msg_sessiond
;
1350 case LTTNG_CONSUMER_CLOSE_METADATA
:
1354 ret
= close_metadata(msg
.u
.close_metadata
.key
);
1359 goto end_msg_sessiond
;
1361 case LTTNG_CONSUMER_FLUSH_CHANNEL
:
1365 ret
= flush_channel(msg
.u
.flush_channel
.key
);
1370 goto end_msg_sessiond
;
1372 case LTTNG_CONSUMER_PUSH_METADATA
:
1375 uint64_t len
= msg
.u
.push_metadata
.len
;
1376 uint64_t key
= msg
.u
.push_metadata
.key
;
1377 uint64_t offset
= msg
.u
.push_metadata
.target_offset
;
1378 struct lttng_consumer_channel
*channel
;
1380 DBG("UST consumer push metadata key %" PRIu64
" of len %" PRIu64
, key
,
1383 channel
= consumer_find_channel(key
);
1385 ERR("UST consumer push metadata %" PRIu64
" not found", key
);
1386 ret_code
= LTTNG_ERR_UST_CHAN_NOT_FOUND
;
1387 goto end_msg_sessiond
;
1390 /* Tell session daemon we are ready to receive the metadata. */
1391 ret
= consumer_send_status_msg(sock
, LTTNG_OK
);
1393 /* Somehow, the session daemon is not responding anymore. */
1397 /* Wait for more data. */
1398 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
1402 ret
= lttng_ustconsumer_recv_metadata(sock
, key
, offset
,
1405 /* error receiving from sessiond */
1409 goto end_msg_sessiond
;
1412 case LTTNG_CONSUMER_SETUP_METADATA
:
1416 ret
= setup_metadata(ctx
, msg
.u
.setup_metadata
.key
);
1420 goto end_msg_sessiond
;
1422 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL
:
1424 if (msg
.u
.snapshot_channel
.metadata
) {
1425 ret
= snapshot_metadata(msg
.u
.snapshot_channel
.key
,
1426 msg
.u
.snapshot_channel
.pathname
,
1427 msg
.u
.snapshot_channel
.relayd_id
,
1430 ERR("Snapshot metadata failed");
1431 ret_code
= LTTNG_ERR_UST_META_FAIL
;
1434 ret
= snapshot_channel(msg
.u
.snapshot_channel
.key
,
1435 msg
.u
.snapshot_channel
.pathname
,
1436 msg
.u
.snapshot_channel
.relayd_id
,
1437 msg
.u
.snapshot_channel
.max_stream_size
,
1440 ERR("Snapshot channel failed");
1441 ret_code
= LTTNG_ERR_UST_CHAN_FAIL
;
1445 ret
= consumer_send_status_msg(sock
, ret_code
);
1447 /* Somehow, the session daemon is not responding anymore. */
1460 * Return 1 to indicate success since the 0 value can be a socket
1461 * shutdown during the recv() or send() call.
1467 * The returned value here is not useful since either way we'll return 1 to
1468 * the caller because the session daemon socket management is done
1469 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1471 ret
= consumer_send_status_msg(sock
, ret_code
);
1480 * Free channel here since no one has a reference to it. We don't
1481 * free after that because a stream can store this pointer.
1483 destroy_channel(channel
);
1485 /* We have to send a status channel message indicating an error. */
1486 ret
= consumer_send_status_channel(sock
, NULL
);
1488 /* Stop everything if session daemon can not be notified. */
1495 /* This will issue a consumer stop. */
1500 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1501 * compiled out, we isolate it in this library.
1503 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream
*stream
,
1507 assert(stream
->ustream
);
1509 return ustctl_get_mmap_read_offset(stream
->ustream
, off
);
1513 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1514 * compiled out, we isolate it in this library.
1516 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream
*stream
)
1519 assert(stream
->ustream
);
1521 return ustctl_get_mmap_base(stream
->ustream
);
1525 * Take a snapshot for a specific fd
1527 * Returns 0 on success, < 0 on error
1529 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream
*stream
)
1532 assert(stream
->ustream
);
1534 return ustctl_snapshot(stream
->ustream
);
1538 * Get the produced position
1540 * Returns 0 on success, < 0 on error
1542 int lttng_ustconsumer_get_produced_snapshot(
1543 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1546 assert(stream
->ustream
);
1549 return ustctl_snapshot_get_produced(stream
->ustream
, pos
);
1553 * Get the consumed position
1555 * Returns 0 on success, < 0 on error
1557 int lttng_ustconsumer_get_consumed_snapshot(
1558 struct lttng_consumer_stream
*stream
, unsigned long *pos
)
1561 assert(stream
->ustream
);
1564 return ustctl_snapshot_get_consumed(stream
->ustream
, pos
);
1568 * Called when the stream signal the consumer that it has hang up.
1570 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream
*stream
)
1573 assert(stream
->ustream
);
1575 ustctl_flush_buffer(stream
->ustream
, 0);
1576 stream
->hangup_flush_done
= 1;
1579 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel
*chan
)
1582 assert(chan
->uchan
);
1584 if (chan
->switch_timer_enabled
== 1) {
1585 consumer_timer_switch_stop(chan
);
1587 consumer_metadata_cache_destroy(chan
);
1588 ustctl_destroy_channel(chan
->uchan
);
1591 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream
*stream
)
1594 assert(stream
->ustream
);
1596 if (stream
->chan
->switch_timer_enabled
== 1) {
1597 consumer_timer_switch_stop(stream
->chan
);
1599 ustctl_destroy_stream(stream
->ustream
);
1602 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
1603 struct lttng_consumer_local_data
*ctx
)
1605 unsigned long len
, subbuf_size
, padding
;
1609 struct ustctl_consumer_stream
*ustream
;
1612 assert(stream
->ustream
);
1615 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream
->wait_fd
,
1618 /* Ease our life for what's next. */
1619 ustream
= stream
->ustream
;
1621 /* We can consume the 1 byte written into the wait_fd by UST */
1622 if (!stream
->hangup_flush_done
) {
1626 readlen
= read(stream
->wait_fd
, &dummy
, 1);
1627 } while (readlen
== -1 && errno
== EINTR
);
1628 if (readlen
== -1) {
1634 /* Get the next subbuffer */
1635 err
= ustctl_get_next_subbuf(ustream
);
1637 ret
= err
; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1639 * This is a debug message even for single-threaded consumer,
1640 * because poll() have more relaxed criterions than get subbuf,
1641 * so get_subbuf may fail for short race windows where poll()
1642 * would issue wakeups.
1644 DBG("Reserving sub buffer failed (everything is normal, "
1645 "it is due to concurrency) [ret: %d]", err
);
1648 assert(stream
->chan
->output
== CONSUMER_CHANNEL_MMAP
);
1649 /* Get the full padded subbuffer size */
1650 err
= ustctl_get_padded_subbuf_size(ustream
, &len
);
1653 /* Get subbuffer data size (without padding) */
1654 err
= ustctl_get_subbuf_size(ustream
, &subbuf_size
);
1657 /* Make sure we don't get a subbuffer size bigger than the padded */
1658 assert(len
>= subbuf_size
);
1660 padding
= len
- subbuf_size
;
1661 /* write the subbuffer to the tracefile */
1662 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, subbuf_size
, padding
);
1664 * The mmap operation should write subbuf_size amount of data when network
1665 * streaming or the full padding (len) size when we are _not_ streaming.
1667 if ((ret
!= subbuf_size
&& stream
->net_seq_idx
!= (uint64_t) -1ULL) ||
1668 (ret
!= len
&& stream
->net_seq_idx
== (uint64_t) -1ULL)) {
1670 * Display the error but continue processing to try to release the
1671 * subbuffer. This is a DBG statement since any unexpected kill or
1672 * signal, the application gets unregistered, relayd gets closed or
1673 * anything that affects the buffer lifetime will trigger this error.
1674 * So, for the sake of the user, don't print this error since it can
1675 * happen and it is OK with the code flow.
1677 DBG("Error writing to tracefile "
1678 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1679 ret
, len
, subbuf_size
);
1681 err
= ustctl_put_next_subbuf(ustream
);
1689 * Called when a stream is created.
1691 * Return 0 on success or else a negative value.
1693 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
1699 /* Don't create anything if this is set for streaming. */
1700 if (stream
->net_seq_idx
== (uint64_t) -1ULL && stream
->chan
->monitor
) {
1701 ret
= utils_create_stream_file(stream
->chan
->pathname
, stream
->name
,
1702 stream
->chan
->tracefile_size
, stream
->tracefile_count_current
,
1703 stream
->uid
, stream
->gid
);
1707 stream
->out_fd
= ret
;
1708 stream
->tracefile_size_current
= 0;
1717 * Check if data is still being extracted from the buffers for a specific
1718 * stream. Consumer data lock MUST be acquired before calling this function
1719 * and the stream lock.
1721 * Return 1 if the traced data are still getting read else 0 meaning that the
1722 * data is available for trace viewer reading.
1724 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream
*stream
)
1729 assert(stream
->ustream
);
1731 DBG("UST consumer checking data pending");
1733 ret
= ustctl_get_next_subbuf(stream
->ustream
);
1735 /* There is still data so let's put back this subbuffer. */
1736 ret
= ustctl_put_subbuf(stream
->ustream
);
1738 ret
= 1; /* Data is pending */
1742 /* Data is NOT pending so ready to be read. */
1750 * Close every metadata stream wait fd of the metadata hash table. This
1751 * function MUST be used very carefully so not to run into a race between the
1752 * metadata thread handling streams and this function closing their wait fd.
1754 * For UST, this is used when the session daemon hangs up. Its the metadata
1755 * producer so calling this is safe because we are assured that no state change
1756 * can occur in the metadata thread for the streams in the hash table.
1758 void lttng_ustconsumer_close_metadata(struct lttng_ht
*metadata_ht
)
1761 struct lttng_ht_iter iter
;
1762 struct lttng_consumer_stream
*stream
;
1764 assert(metadata_ht
);
1765 assert(metadata_ht
->ht
);
1767 DBG("UST consumer closing all metadata streams");
1770 cds_lfht_for_each_entry(metadata_ht
->ht
, &iter
.iter
, stream
,
1772 int fd
= stream
->wait_fd
;
1775 * Whatever happens here we have to continue to try to close every
1776 * streams. Let's report at least the error on failure.
1778 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1780 ERR("Unable to close metadata stream fd %d ret %d", fd
, ret
);
1782 DBG("Metadata wait fd %d closed", fd
);
1787 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream
*stream
)
1791 ret
= ustctl_stream_close_wakeup_fd(stream
->ustream
);
1793 ERR("Unable to close wakeup fd");
1797 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data
*ctx
,
1798 struct lttng_consumer_channel
*channel
)
1800 struct lttcomm_metadata_request_msg request
;
1801 struct lttcomm_consumer_msg msg
;
1802 enum lttng_error_code ret_code
= LTTNG_OK
;
1803 uint64_t len
, key
, offset
;
1807 assert(channel
->metadata_cache
);
1809 /* send the metadata request to sessiond */
1810 switch (consumer_data
.type
) {
1811 case LTTNG_CONSUMER64_UST
:
1812 request
.bits_per_long
= 64;
1814 case LTTNG_CONSUMER32_UST
:
1815 request
.bits_per_long
= 32;
1818 request
.bits_per_long
= 0;
1822 request
.session_id
= channel
->session_id
;
1823 request
.session_id_per_pid
= channel
->session_id_per_pid
;
1824 request
.uid
= channel
->uid
;
1825 request
.key
= channel
->key
;
1826 DBG("Sending metadata request to sessiond, session id %" PRIu64
1827 ", per-pid %" PRIu64
,
1828 channel
->session_id
,
1829 channel
->session_id_per_pid
);
1831 ret
= lttcomm_send_unix_sock(ctx
->consumer_metadata_socket
, &request
,
1834 ERR("Asking metadata to sessiond");
1838 /* Receive the metadata from sessiond */
1839 ret
= lttcomm_recv_unix_sock(ctx
->consumer_metadata_socket
, &msg
,
1841 if (ret
!= sizeof(msg
)) {
1842 DBG("Consumer received unexpected message size %d (expects %zu)",
1844 lttng_consumer_send_error(ctx
, LTTCOMM_CONSUMERD_ERROR_RECV_CMD
);
1846 * The ret value might 0 meaning an orderly shutdown but this is ok
1847 * since the caller handles this.
1852 if (msg
.cmd_type
== LTTNG_ERR_UND
) {
1853 /* No registry found */
1854 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1858 } else if (msg
.cmd_type
!= LTTNG_CONSUMER_PUSH_METADATA
) {
1859 ERR("Unexpected cmd_type received %d", msg
.cmd_type
);
1864 len
= msg
.u
.push_metadata
.len
;
1865 key
= msg
.u
.push_metadata
.key
;
1866 offset
= msg
.u
.push_metadata
.target_offset
;
1868 assert(key
== channel
->key
);
1870 DBG("No new metadata to receive for key %" PRIu64
, key
);
1873 /* Tell session daemon we are ready to receive the metadata. */
1874 ret
= consumer_send_status_msg(ctx
->consumer_metadata_socket
,
1876 if (ret
< 0 || len
== 0) {
1878 * Somehow, the session daemon is not responding anymore or there is
1879 * nothing to receive.
1884 ret_code
= lttng_ustconsumer_recv_metadata(ctx
->consumer_metadata_socket
,
1885 key
, offset
, len
, channel
);
1886 if (ret_code
>= 0) {
1888 * Only send the status msg if the sessiond is alive meaning a positive
1891 (void) consumer_send_status_msg(ctx
->consumer_metadata_socket
, ret_code
);